.HeaderImg{
  .ActivityHeader{
    height: 50vw;
    justify-content:center;//子元素水平居中
    align-items:center;//子元素垂直居中
    display:-webkit-flex;
    text-align: center;
    position: relative;
    background: none;
    >div{
      z-index: 1;
      background: none;
      color:#fff;
      font-size: 5vw;
      p:nth-child(1){
        font-size: 6vw;
        margin-bottom: 4vw;
      }
    }
    >img{
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top:0;
      background: #fff;
      z-index: 0;
    }
  }
}